Firefox only: Firefox has long had a handy built-in spell checker, great for proofreading emails, blog posts, and other communications. What if you want to use the built-in spell checker on a static web page however? Use this bookmarklet.

By dragging and dropping the simple bookmarklet below to your bookmark toolbar, you can activate the spell checker on any static page.

Not only can you see the errors, but because the bookmarklet sets the text content of the page to editable, you can actively correct your mistakes, preventing copy-and-paste errors down the line. It's a handy way to proof a draft sent to you via email, or make some corrections to a text you're copying and pasting.

Have any handy bookmarklets—Firefox-centric or otherwise—to share? Throw them in the comments below.